Sheet feeder and image reader having the same

ABSTRACT

A sheet feeder including a motor, a shaft configured to be driven to rotate by a driving force from the motor, the shaft being spaced apart from the motor in an axial direction of the shaft, the shaft being disposed to overlap in a view in the axial direction of the shaft, and a roller supported by the shaft and rotatable along with the shaft, the roller being configured to convey the sheet downstream in a sheet conveyance direction along a sheet conveyance path.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 from JapanesePatent Application No. 2014-015633 filed on Jan. 30, 2014. The entiresubject matter of the application is incorporated herein by reference.

BACKGROUND

1. Technical Field

The following description relates to aspects of a sheet feeder and animage reader having the sheet feeder.

2. Related Art

An automatic document feeder (hereinafter referred to as an “ADF” in anabbreviation form) of an image reader has been known that includesrotational shafts, motors configured to drive and rotate the rotationalshafts, and rollers each configured to rotate together with acorresponding one of the rotational shafts and feed sheets downstream ina sheet feeding direction.

For instance, the known automatic document feeder includes a firstmotor, a pickup roller, a separation roller, a registration roller, anda turn-around roller. The pickup roller, the separation roller, theregistration roller, and the turn-around roller are driven to rotate bythe first motor. The automatic document feeder further includes a secondmotor, a pre-reading roller, a reading roller, a post-reading roller,and a discharge roller. The pre-reading roller, the reading roller, thepost-reading roller, and the discharge roller are driven to rotate bythe second motor. The first motor and the second motor are disposed notto overlap any of the aforementioned various rollers in a view in anaxial direction of each roller.

SUMMARY

However, when the above elements such as the various rollers and thefirst and second motors are disposed based on the aforementionedpositional relationship thereamong, it requires a large region occupiedby the elements in the view in the axial direction of each roller.Consequently, the ADF as a whole needs to be large in size. Therefore,when the ADF is required to be made smaller or thinner, it might beimpossible to apply the aforementioned positional relationship among theelements included in the ADF. Thus, it requires some ingenuity toachieve miniaturization of the ADF.

Aspects of the present disclosure are advantageous to provide one ormore improved techniques for realizing an ADF smaller in size than theknown ADF.

According to aspects of the present disclosure, a sheet feeder isprovided, which includes a motor, a first shaft configured to be drivento rotate by a driving force from the motor, the first shaft beingspaced apart from the motor in an axial direction of the first shaft,the first shaft being disposed to overlap in a view in the axialdirection of the first shaft, and a first roller supported by the firstshaft and rotatable along with the first shaft, the first roller beingconfigured to convey the sheet downstream in a sheet conveyancedirection along a sheet conveyance path.

According to aspects of the present disclosure, further provided is animage reader that includes an image sensor configured to read an imageon a sheet in a reading position, and a sheet feeder configured to feedthe sheet to the reading position and discharge the sheet on which theimage has been read by the image sensor, the sheet feeder including amotor, a first shaft configured to be driven to rotate by a drivingforce from the motor, the first shaft being spaced apart from the motorin an axial direction of the first shaft, the first shaft being disposedto overlap in a view in the axial direction of the first shaft, and afirst roller supported by the first shaft and rotatable along with thefirst shaft, the first roller being configured to convey the sheetdownstream in a sheet conveyance direction along a sheet conveyancepath.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIG. 1 is a perspective view of a multi-function peripheral(hereinafter, which may be referred to as an MFP in an abbreviationform) in an illustrative embodiment according to one or more aspects ofthe present disclosure.

FIG. 2A is a cross-sectional front view showing an internalconfiguration of a reading unit of the MFP in a state where a firstcover is closed, in the illustrative embodiment according to one or moreaspects of the present disclosure.

FIG. 2B is a cross-sectional front view showing an internalconfiguration of the reading unit of the MFP in a state where the firstcover is open, in the illustrative embodiment according to one or moreaspects of the present disclosure.

FIG. 3 is a perspective view showing a configuration around an ADFsection of the reading unit to which a second guide member is attached,in the illustrative embodiment according to one or more aspects of thepresent disclosure.

FIG. 4 is a perspective view showing a configuration around the ADFsection of the reading unit from which the second guide member isremoved, in the illustrative embodiment according to one or more aspectsof the present disclosure.

FIG. 5 is a perspective view showing a motor, rollers to be driven by adriving force from the motor, and power transmission units fortransmitting the driving force from the motor to the rollers in theillustrative embodiment according to one or more aspects of the presentdisclosure.

FIG. 6 is a cross-sectional front view showing a configuration around afirst guide member and the second guide member in the illustrativeembodiment according to one or more aspects of the present disclosure.

FIG. 7A is a rear view showing a first power transmission unit in theillustrative embodiment according to one or more aspects of the presentdisclosure.

FIG. 7B is a rear view showing a supporting wall including a first sheetmetal member and a second sheet metal member in the illustrativeembodiment according to one or more aspects of the present disclosure.

FIG. 8A is a perspective view showing the first sheet metal member inthe illustrative embodiment according to one or more aspects of thepresent disclosure.

FIG. 8B is a perspective view showing the second sheet metal member inthe illustrative embodiment according to one or more aspects of thepresent disclosure.

FIG. 9 is a front view showing a second power transmission unit, and themotor, the supporting wall, and the first power transmission unit behindthe second power transmission unit in the illustrative embodimentaccording to one or more aspects of the present disclosure.

FIG. 10 is a perspective view showing the first guide member in theillustrative embodiment according to one or more aspects of the presentdisclosure.

DETAILED DESCRIPTION

It is noted that various connections are set forth between elements inthe following description. It is noted that these connections in generaland, unless specified otherwise, may be direct or indirect and that thisspecification is not intended to be limiting in this respect.

Hereinafter, a multi-function peripheral 1 (hereinafter referred to asan “MFP 1”) of an illustrative embodiment according to aspects of thepresent disclosure will be described with reference to the accompanyingdrawings. In the following description, a vertical direction, aleft-to-right direction, and a front-to-rear direction of the MFP willbe defined as shown in the accompanying drawings, for the sake of simpleexplanations on relative positional relationship among elements includedin the MFP 1.

[Configuration of MFP]

The MFP 1 includes a main body unit 2 and a reading unit 3 disposedabove the main body unit 2. The reading unit 3 is attached to the mainbody unit 2 to be openable and closable relative to the main body unit2. When the reading unit 3 is closed, an opening formed at an upper faceside of the main body unit 2 is closed by the reading unit 3.

The reading unit 3 includes a flatbed section 4 (hereinafter referred toas an “FB section 4”) and an ADF section 5 disposed above the FB section4. The ADF section 5 is attached to the FB section 4 to be openable andclosable relative to the FB section 4. When the ADF section 5 is closed,the ADF section 5 serves as a cover for covering an upper face side ofthe FB section 4.

Inside the main body unit 2, a controller, an image forming section, andan LAN communication section are disposed. Further, an operation panel 7is disposed at an upper front portion of the main body unit 2. Theoperation panel 7 is configured to be operated by a user. At a lowerportion of the operation panel 7, an output port 8 is disposed. Theoutput port 8 is configured to discharge therethrough a recording medium(such as a recording sheet) on which an image has been formed by theimage forming section. Namely, the user is allowed to take out therecording medium with the image formed thereon from the output port 8.Below the output port 8, a medium supply cassette 9 is attached. Themedium supply cassette 9 is configured to accommodate recording media(such as recording sheets) to be supplied to the image forming section.

In the reading unit 3, as shown in FIGS. 2A and 2B, the ADF section 5includes a sheet conveyor 10 configured to convey document sheets alonga sheet conveyance path (see a bold dashed arrow in FIG. 2B). The sheetconveyor 10 includes a pickup roller 11, a separation roller 12A, aseparation pad 12B, a relay roller 13, a turn-around roller 14A, anupper pinch roller 14B, a lower pinch roller 14C, a discharge roller15A, and a discharge pinch roller 15B.

As shown in FIGS. 1, 2A, and 2B, there are a first cover 16, a secondcover 17, and a third cover 18 disposed at an upper face side of the ADFsection 5. The first cover 16, the second cover 17, and the third cover18, together with an ADF base member 5A, form an exterior of the ADFsection 5. The ADF base member 5A forms a bottom portion and side wallsof the ADF section 5.

The first cover 16 is configured to rotate around a rotational shaft16A, between a retracted position shown in FIG. 2A and a usage positionshown in FIG. 2B. The rotational shaft 16A is disposed close to a rightend portion of the first cover 16 in the retracted position. The thirdcover 18 is configured to rotate around a rotational shaft 18A, betweena horizontal position shown in FIG. 2A and a slanted position shown inFIG. 2B. The rotational shaft 18A is disposed close to a right endportion of the third cover 18.

In the state shown in FIG. 2A, a boss (not shown), which is disposed ata distal end of an arm 16B extending from the first cover 16, isinserted into an arm receiver 18B that is formed on a lower surface ofthe third cover 18. Thus, the boss supports the third cover 18 fromunderneath. Namely, in the state shown in FIG. 2A, as the arm 16Bextending from the first cover 16 supports the third cover 18 fromunderneath, the first cover 16 and the third cover 18 forms a horizontalsurface. It is noted that the “horizontal surface” means not only acompletely horizontal plane surface but also a substantially horizontalsurface that may include some concave and convex portions and someslanted portions. Then, in this state, when the first cover is rotatedfrom the retracted position to the usage position, the boss of the arm16B moves downward, and a left end portion of the third cover 18 movesdownward. Thereby, the third cover 18 is rotated from the horizontalposition shown in FIG. 2A to the slanted position shown in FIG. 2B, inconjunction with rotation of the first cover 16.

When the first cover 16 moves from the retracted position to the usageposition, the third cover 18 reaches the slanted position before thefirst cover 16 reaches the usage position. After that, the boss of thearm 16B gets out of the arm receiver 18B, and the first cover 16 reachesthe usage position without displacing the third cover 18 (i.e., withmaintaining the slanted position of the third cover 18). Further, whenmoving from the usage position to the retracted position, initially, thefirst cover 16 rotates without displacing the third cover 18.Nevertheless, the boss of the arm 16B is inserted into the arm receiver18B before the first cover 16 reaches the retracted position. Afterthat, thereby, the boss of the arm 16B lifts up the left end portion ofthe third cover 18 until the first cover 16 reaches the retractedposition. Thus, the third cover 18 rotates in conjunction with rotationof the first cover 16, and reaches the horizontal position substantiallyat the same time when the first cover 16 reaches the retracted position.

When the first cover 16 moves to the usage position, a first supporter21 and a second supporter 22 are formed at the ADF section 5. The firstsupporter 21 is configured to support, from underneath, document sheetsto be supplied to the sheet conveyor 10. The second supporter 22 isconfigured to support, from underneath, the document sheets dischargedfrom the sheet conveyor 10. The first supporter 21 and the secondsupporter 22 are disposed to at least partially overlap each other in aview in the vertical direction. Further, the first supporter 21 and thesecond supporter 22 are spaced apart from each other in the verticaldirection. The first supporter 21 is positioned above the secondsupporter 22 (i.e., the second supporter 22 is positioned below thefirst supporter 21).

As shown in FIGS. 2A and 2B, the first supporter 21 includes a firsttray 211, a second tray 212, and a third tray 213. The first tray 211 isconfigured to support the document sheets in a position closer to thesheet conveyor 10 than the second tray 212 and the third tray 213. Thesecond tray 212 is configured to support the document sheets in aposition farther from the sheet conveyor 10 than the first tray 211. Thethird tray 213 is configured to support the document sheets in aposition farther from the sheet conveyor 10 than the second tray 212.The second supporter 22 includes a fourth tray 224 and a fifth tray 225.The fourth tray 224 is configured to support the document sheets in aposition closer to the sheet conveyor 10 than the fifth tray 225. Thefifth tray 225 is configured to support the document sheets in aposition farther from the sheet conveyor 10 than the fourth tray 224.The fifth tray 225 is formed by a surface of the first cover 16. Thethird tray 213 is fixedly attached to the surface of the first cover 16,to be spaced apart from the fifth tray 225. Therefore, when the firstcover 16 is in the usage position, the third tray 213 is disposed in aposition where the third tray 213 forms a part of the first supporter21, and the fifth tray 225 is disposed in a position where the fifthtray 225 forms a part of the second supporter 22. When the first cover16 is moved to the retracted position, the first cover 16 is placed intoa state to cover upper sides of the first tray 211 and the second tray212. At this time, the other surface of the first cover 16 faces upward.The third tray 213 and the fifth tray 225, which have moved along withmovement of the first cover 16 to the retracted position, are put insidethe ADF section 5 in a state where sheet supporting surfaces of thetrays 213 and 225 are oriented to face downward.

Document sheets placed on the first supporter 21 is conveyed along thesheet conveyance path indicated by the bold dashed arrow in FIG. 2B, anddischarged onto the second supporter 22. At that time, the documentsheets, fed downstream from the first supporter 21 in a sheet conveyancedirection by the pickup roller 11, are separated on a sheet-by-sheetbasis by the separation roller 12A and the separation pad 12B. Then, thedocument sheets are further conveyed downstream in the sheet conveyancedirection by the relay roller 13 and the turn-around roller 15A, anddischarged onto the second supporter 22 by the discharge roller 15A.

A first transparent portion 25A and a first document pressing member 27Aare disposed in a position between the turn-around roller 14A and thedischarge roller 15A, along the sheet conveyance path. Further, a secondtransparent portion 25B and a second document pressing member 27B aredisposed in a position between the relay roller 13 and the turn-aroundroller 14A, along the sheet conveyance path.

The first transparent portion 25A is disposed in the FB section 4. Thesecond transparent portion 25B, the first document pressing member 27A,and the second document pressing member 27B are disposed in the ADFsection 5. In the present embodiment, each of the first transparentportion 25A and the second transparent portion 25B is formed by a glassplate. Each of the first transparent portion 25A and the secondtransparent portion 25B extends over a range more than a length of thedocument sheets in a width direction (i.e., the front-to-rear direction)perpendicular to the sheet conveyance direction.

Each of the first document pressing member 27A and the second documentpressing member 27B is made of metal or hard resin material. Each of thefirst document pressing member 27A and the second document pressingmember 27B extends over a range more than the length of the documentsheets in the width direction, in the same manner as the firsttransparent portion 25A and the second transparent portion 25B.

The first document pressing member 27A is urged toward the firsttransparent portion 25A by a spring (not shown). Thereby, the firstdocument pressing member 27A prevents a document sheet, which is passingover the first transparent portion 25A while contacting an upper surfaceof the first transparent portion 25A, from floating from the firsttransparent portion 25A. The second document pressing member 27B isurged toward the second transparent portion 25B by a spring (not shown).Thereby, the second document pressing member 27B prevents a documentsheet, which is passing over the second transparent portion 25B whilecontacting an upper surface of the second transparent portion 25B, fromfloating from the second transparent portion 25B.

In addition, there is a third transparent portion 25C disposed in the FBsection 4. Further, there is a third document pressing member 27Cdisposed in the ADF section 5. The third transparent portion 25C isformed by a glass plate, in the same manner as the first transparentportion 25A and the second transparent portion 25B. However, the thirdtransparent portion 25C is different from the first transparent portion25A and the second transparent portion 25B in the following point. Thatis, the third transparent portion 25C has an area wide enough for adocument sheet to be entirely put thereon.

The third document pressing member 27C is formed by a laminated bodythat includes a formed resin layer and a hard resin film layer. When theADF section 5 is closed, the third document pressing member 27C comesinto close contact with the third transparent portion 25C while beingslightly and elastically deformed. Thereby, the third document pressingmember 27C prevents a document sheet placed on the third transparentportion 25C from floating from the third transparent portion 25C.

In the FB section 4, a guiderail 29, a carriage 30, and a first imagesensor 31A are disposed. In the ADF section 5, a second image sensor 31Bis disposed. The guiderail 29 is formed integrally on an inner surfaceof a bottom portion of a housing 4A of the FB section 4. The guiderail29 extends in the left-to-right direction, parallel to lower surfaces ofthe first transparent portion 25A and the third transparent portion 25C,over a range from a position under the first transparent portion 25A toa position under the third transparent portion 25C.

The carriage 30 is attached to an upper portion of the guiderail 29.Thereby, the carriage 30 is supported to reciprocate along the guiderail29 in the left-to-right direction. The carriage 30 is connected with atiming belt (not shown). The carriage 30 reciprocates along theleft-to-right direction in response to the timing belt being driven torevolve.

In the illustrative embodiment, as each of the first image sensor 31Aand the second image sensor 31B, a contact image sensor (hereinafterreferred to as a “CIS” in an abbreviation form) is used. The first imagesensor 31A is mounted on the carriage 30, and configured to reciprocatealong the left-to-right direction together with the carriage 30.

There is a spring (not shown) disposed between the first image sensor31A and the carriage 30. The first image sensor 31A is urged upward bythe spring. Further, a spacer is attached to each of two end portions ofthe first image sensor 31A in the front-to-rear direction. The spacers,urged upward together with the first image sensor 31A, are configured tocontact the lower surface of the third transparent portion 25C or thelower surface of the first transparent portion 25A.

Thereby, when the first image sensor 31A reciprocates along theleft-to-right direction together with the carriage 30, the spacersmaintains a contact state where the spacers are in contact with thelower surface of the third transparent portion 25C or the lower surfaceof the first transparent portion 25A. Thus, the first image sensor 31Amoves while maintaining a constant distance from the third transparentportion 25C and the first transparent portion 25A in the verticaldirection.

The second image sensor 31B is unmovably disposed in a predeterminedposition. The second image sensor 31B is urged toward the secondtransparent portion 25B by a spring (not shown). Thereby, a distancebetween the second image sensor 31B and the second transparent portion25B is maintained constant.

Each of the first image sensor 31A and the second image sensor 31B has aplurality of reading elements arranged in the front-to-rear direction.When reading an image of a document sheet placed on an upper surface ofthe third transparent portion 25C, the first image sensor 31A reads theimage while moving along with the carriage 30.

Further, when reading images of a document sheet being conveyed by thesheet conveyor 10, the first image sensor 31A reads an image on a sideof the document sheet passing over and in contact with an upper surfaceof the first transparent portion 25A, in a static state where the firstimage sensor 31A is staying in a position under the first documentpressing member 27A and the first transparent portion 25A. The secondimage sensor 31B reads an image on the other side of the document sheetpassing over and in contact with an upper surface of the secondtransparent portion 25B, in a position under the second documentpressing member 27B and the second transparent portion 25B.

[Detailed Configuration of Sheet Conveyor]

Subsequently, a detailed explanation will be provided about aconfiguration of the sheet conveyor 10. In order to drive and rotate thepickup roller 11, the separation roller 12A, the relay roller 13, theturn-around roller 14A, and the discharge roller 15A, as shown in FIGS.3 to 5, the sheet conveyor 10 includes a first power transmission unit41, a second power transmission unit 42, and a third power transmissionunit 43. The first power transmission unit 41, the second powertransmission unit 42, and the third power transmission unit 43 aredisposed on an upper surface side of the ADF base member 5A. Further, asshown in FIGS. 3, 4, and 6, a first guide member 46 and a second guidemember 47 are disposed on the upper surface side of the ADF base member5A.

FIG. 4 shows a state in which the second guide member 47 shown in FIG. 3is removed. Thus, in FIG. 4, it is possible to see elements that arehidden under the second guide member 47 and invisible in FIG. 3. In FIG.5, elements, which are shown in FIG. 4 and other than the sheet conveyor10, are omitted. Thus, in FIG. 5, it is possible to see elements thatare hidden under the first guide member 46 and invisible in FIG. 4.

The first guide member 46 and the second guide member 47 are members fordefining the sheet conveyance path (see the bold dashed arrow in FIG.2B). Specifically, the first guide member 46 is configured to, whenattached to the ADF base member 5A, form (define) a downstream sheetconveyance path between the first guide member 46 and the ADF basemember 5A. The downstream sheet conveyance path leads to the dischargeroller 15A from the turn-around roller 14A. The second guide member 47is disposed in a position that is opposite to the downstream sheetconveyance path with respect to the first guide member 46. The secondguide member 47 is configured to form an upstream sheet conveyance pathbetween the second guide member 47 and the second cover 17 that isdisposed opposite to the first guide member 46 with respect to thesecond guide member 47. The upstream sheet conveyance path leads to theturn-around roller 14 from an upstream position relative to theturn-around roller 14A in the sheet conveyance direction. Namely, aroundthe sheet conveyor 10, the sheet conveyance path passes over an uppersurface side of the second guide member 47, and reaches a left endportion of the second guide member 47. Thereafter, the sheet conveyancepath turns downward, then passes under a lower surface side of the firstguide member 46, and reaches a right end portion of the first guidemember 46.

The pickup roller 11, the separation roller 12A, the relay roller 13,the turn-around roller 14A, and the discharge roller 15A are fixedlyattached to a shaft 51, a shaft 52, a shaft 53, a shaft 54, and a shaft55, respectively. As shown in FIGS. 5 and 7A, gears 41E, 41G, and 41J,of gears 41A to 41J included in the first power transmission unit 41,are fixedly attached to rear end portions of the shafts 52, 53, and 54,respectively. When the first power transmission unit 41 operates inresponse to an operation of a motor 35, the gears 41E, 41G, and 41Jrotates, and thereby, the shafts 52, 53, and 54 are driven to rotate.

As shown in FIGS. 7A and 7B, around the first power transmission unit41, a supporting wall 60 is disposed. As shown in FIGS. 7B, 8A, and 8B,the supporting wall 60 includes a first sheet metal member 61 and asecond sheet metal member 62. The first sheet metal member 61 and thesecond sheet metal member 62 are sheet metal components.

The first sheet metal member 61 includes a first portion 61A, a secondportion 61B, and a third portion 61C. The first portion 61A is a portiondisposed parallel to the sheet conveyance path in a state where a platethickness direction of the first portion 61A is oriented in the samedirection as an axial direction of the shaft 55. The second portion 61Bis a portion that is bent from a left end of the first portion 61A andextends in such a direction as to approach the sheet conveyance path.The third portion 61C is a portion that is bent from a front end of thesecond portion 61B and disposed parallel to the sheet conveyance path ina position closer to the sheet conveyance path than the first portion61A in the front-to-rear direction.

The second sheet metal member 62 includes a fourth portion 62A, a fifthportion 62B, and a sixth portion 62C. The fourth portion 62A is aportion disposed parallel to the sheet conveyance path in a state wherea plate thickness direction of the fourth portion 62A is oriented in thesame direction as an axial direction of the shaft 55. The fifth portion62B is a portion that is bent from a left end of the fourth portion 62Aand extends in such a direction as to become farther from the sheetconveyance path. The sixth portion 62C is a portion that is bent from arear end of the fifth portion 62B and disposed parallel to the sheetconveyance path in a position farther from the sheet conveyance paththan the fourth portion 62A in the front-to-rear direction.

As shown in FIG. 7B, the first sheet metal member 61 has positioningholes 63A and 63B, and screw holes 64A and 64B. The second sheet metalmember 62 has positioning holes 65A and 65B, and screw holes 66A and66B.

The first sheet metal member 61 and the second sheet metal member 62 arefixedly attached to the first guide member 46 with high accuracy.Specifically, the third portion 61C and the fourth portion 62A aredisposed to face and contact each other in their plate thicknessdirection. Then, the positioning hole 63B of the first sheet metalmember 61 and the positioning hole 65B of the second sheet metal member62 are positioned to coincide with each other, and a positioningprojection 67A is inserted into the positioning holes 63B and 65B, asshown in FIG. 7A. The positioning projection 67A is formed to protrudefrom a surface of the first guide member 46. The screw hole 64B of thefirst sheet metal member 61 and the screw hole 66B of the second sheetmetal member 62 are positioned to coincide with each other, and a screw68A is inserted through the screw holes 64B and 66B. Then, the screw 68Ais screwed into the first guide member 46.

Into the positioning hole 63A of the first sheet metal member 61, apositioning projection 67B is inserted. The positioning projection 67Bis formed to protrude from a surface of the first guide member 46. Ascrew 68B is inserted through the screw hole 64A of the first sheetmetal member 61, and then screwed into the first guide member 46. Intothe positioning hole 65A of the second sheet metal member 62, apositioning projection 67C is inserted. The positioning projection 67Cis formed to protrude from the surface of the first guide member 46. Ascrew 68C is inserted through the screw hole 66A of the second sheetmetal member 61, and then screwed into the first guide member 46.

Thus, the first sheet metal member 61 is positioned relative to thefirst guide member 46, on the basis of the two positioning holes 63A and63B. Further, the first sheet metal member 61 is screwed to the firstguide member 46, through the two screw holes 64A and 64B. Likewise, thesecond sheet metal member 62 is positioned relative to the first guidemember 46, on the basis of the two positioning holes 65A and 65B.Further, the second sheet metal member 62 is screwed to the first guidemember 46, through the two screw holes 66A and 66B. Moreover, thepositioning projection 67A is used in common to be inserted into boththe positioning hole 63B of the first sheet metal member 61 and thepositioning hole 65B of the second sheet metal member 62. Further, thescrew 68A is used in common to be inserted through both the screw hole64B of the first sheet metal member 61 and the positioning hole 66B ofthe second sheet metal member 62. Therefore, it is possible toaccurately position the first sheet metal member 61 and the second sheetmetal member 62 relative to the first guide member 46, and to accuratelyposition the first sheet metal member 61 and the second sheet metalmember 62 relative to each other.

The motor 35 is disposed on a surface of the first portion 61A that isclose to the sheet conveyance path (i.e., a frontward-facing surface ofthe first portion 61A that faces the front side of the MFP 1. The motor35 is fixedly attached to the first portion 61A by a screw 68D insertedthrough a screw hole 64C. Further, as shown in FIGS. 7A, 8A, and 8B, ashaft 69B is disposed on a rearward-facing surface of the first portion61A (which faces the rear side of the MFP 1 and is opposite to thefrontward-facing surface of the first portion 61A). Further, a shaft 69Cand a shaft 69F are disposed on a rearward-facing surface of the thirdportion 61C. Further, a shaft 69H and a shaft 69I are disposed on arearward-facing surface of the sixth portion 62C. To the shafts 69B,69C, 69F, 69H, and 69I, gears 41B, 41C, 41F, 41H, and 41I are attached,respectively. Thus, each of the gears 41B, 41C, 41F, 41H, and 41I issupported to be rotatable around an axis extending in the front-to-reardirection. It is noted that the gears 41B, 41C, 41F, 41H, and 41I areincluded in the first power transmission unit 41.

The third portion 61C includes bearings 70A and 70B each formed in acutout shape. The sixth portion 62C includes a bearing 70C formed in acutout shape. Rear end portions of the shafts 52, 53, and 54 aresupported by the bearings 70A, 70B, and 70C (see FIG. 7B) via bushes(with no reference characters shown), respectively. Thereby, the shafts52, 53, and 54 are supported to be rotatable around axes extending inthe front-to-rear direction, respectively.

As shown in FIG. 9, the second power transmission unit 42 is disposed tooverlap the first power transmission unit 41 in a view in an axialdirection of the shafts 54 and 55. Further, the motor 35 and the shaft55 are disposed to overlap each other in a view in the axial directionof the shaft 55. As shown in FIGS. 5 and 9, to front end portions of theshafts 54 and 55, gears 42A and 42B are attached. The gears 42A and 42Bare included in the second power transmission unit 42. There is atoothed belt 42C wound around the gears 42A and 42B. When the firstpower transmission unit 41 operates in response to the operation of themotor 35, and thereby, the shaft 54 is driven to rotate, the secondpower transmission unit 42 operates. Specifically, in response torotation of the gear 42A, the toothed belt 42C is driven to revolve, andthe gear 42 is rotated. Thereby, the shaft 55 is driven to rotate. Atthis time, the shaft 55 is driven to rotate by the toothed belt 42C, inthe same rotational direction as the shaft 54.

As shown in FIGS. 4 and 10, the shaft 55 is attached to bearings 72A and72B, and rotatably supported by the bearings 72A and 72B. The bearings72A and 72B are formed integrally with the first guide member 46. Thebearing 72B, which supports a rear end portion of the shaft 55, isdisposed closer to the sheet conveyance path than the motor 35 in thefront-to-rear direction. The motor 35 and the shaft 55 are spaced apartfrom each other in the axial direction of the shaft 55. The bearing 72Bis formed in such a shape as to have a projection 81. The projection 81protrudes toward the shaft 55 from a portion close to the motor 35, inthe axial direction of the shaft 55. Further, the projection 81 has anopening 83 formed at a leading end, in the protruding direction, ofprojection 81. Thus, the bearing 72B is configured to support the rearend portion of the shaft 55 inserted into an inner circumferential sideof the projection 81 through the opening 83. In the illustrativeembodiment, as shown in FIGS. 4 and 5, there is a bush 73 between thebearing 72B and the shaft 55. The projection 81 is disposed in such aposition that a leading end portion 81A, in the protruding direction, ofthe projection 81 overlaps the sheet conveyance path in a view in adirection perpendicular to the protruding direction of the projection81. It is noted that a plurality of interpretations may be considered asthe definition “the leading end portion 81A of the projection 81overlaps the sheet conveyance path.” For instance, each of the firstguide member 46 and the second guide member 47 has a surface(hereinafter referred to as a conveyance surface) that faces a sheetbeing conveyed thereon. In general, an apparatus of this kind includesside walls that are disposed at two ends of a conveyance surface in awidth direction of a sheet, respectively, and extend in a directionperpendicular to the conveyance surface. Namely, the sheet is conveyedalong and passes through a sheet conveyance path defined by theconveyance surface and the side walls. In this case, when the leadingend portion 81A of the projection 81 protrudes toward the sheetconveyance path from one of the two side walls, it may be interpreted as“the leading end portion 81A of the projection 81 overlapping the sheetconveyance path.” Further, in the apparatus of this kind, a maximumwidth of sheets conveyable by the apparatus is previously determined. Inthis case, a range through which the sheets of the maximum width passmay be defined as the sheet conveyance path. Namely, when the leadingend portion 81A of the projection 81 is at least partially within therange through which the sheets of the maximum width pass, it may beinterpreted as “the leading end portion 81A of the projection 81overlapping the sheet conveyance path.”

The second guide member 47 is disposed very close to the bearing 72B.However, as shown in FIG. 3, the second guide member 47 includes acutout portion 75, and the bearing 72B is partially put inside thecutout portion 75. Therefore, although the bearing 72B is disposed insuch a position as above, it is possible to dispose the second guidemember 47 sufficiently close to the first guide member 46. Accordingly,it is possible to thin a multi-layer structure that the second guidemember 47 is placed above the first guide member 46. Thus, it ispossible to make the ADF section 5 thinner than when the aforementionedthinned multi-layer structure of the two guide members 46 and 47 is notemployed.

As shown in FIG. 5, there is a gear 43A attached between two ends of theshaft 52 in an axial direction of the shaft 52. In addition, there is agear 43B attached to a rear end portion of the shaft 51. Further, thereis a gear 43C disposed between the gears 43A and 43B. The gears 43A,43B, and 43C are included in the third power transmission unit 43. Whenthe first power transmission unit 41 operates in response to theoperation of the motor 35, and the shaft 52 is driven to rotate, thethird power transmission unit 43 operates, and the shaft 51 is driven torotate.

Advantageous Effects

According to the MFP 1 as described above, in the ADF section 5, themotor 35 and the shaft 55 are disposed not to overlap each other in theaxial direction of the shaft 55 (i.e., not overlap each other in a viewin a direction perpendicular to the axial direction of the shaft 55) anddisposed to overlap each other in a view in the axial direction of theshaft 55. Therefore, in the view in the axial direction of the shaft 55,there is no need to secure a space for disposing the shaft 55 around themotor 35, unlike when an equivalent of the motor 35 and an equivalent ofthe shaft 55 are disposed to overlap each other in an axial direction ofthe equivalent of the shaft 55 and not overlap each other in a view inthe axial direction of the equivalent of the shaft 55. Therefore, it ispossible to achieve miniaturization of the ADF section 5.

Further, according to the aforementioned ADF section 5, in the bearing72B closer to the motor 35 (than the bearing 72A), the projection 81 isdisposed in such a position that the leading end portion 81A, in theprotruding direction, of the projection 81 overlaps the sheet conveyancepath in a view in a direction perpendicular to the protruding directionof the projection 81 (e.g., in a top view or a bottom view). Therefore,it is possible to make shorter a length of the shaft 55 in the axialdirection of the shaft 55 and/or a distance between the bearings 72A and72B, than when an equivalent of the projection 81 is disposed not tooverlap the sheet conveyance path in a view in a direction perpendicularto a protruding direction of the equivalent of the projection 81.Accordingly, although the motor 35 and the shaft 55 are disposed in suchpositions as described above, it is possible to dispose the motor 35closer to the sheet conveyance path in comparison with a knownconfiguration. Thereby, it is possible to achieve miniaturization of theADF section 5 as a whole.

Further, according to the aforementioned ADF section 5, the bearing 72Bis formed integrally with the first guide member 46. Therefore, it ispossible to make the number of components and assembling man-hours lessthan when a bearing is provided as a body separate from the first guidemember 46.

Further, according to the aforementioned ADF section 5, the bearing 72Bis partially put inside the cutout portion 75 formed at the second guidemember 47. Therefore, it is possible to dispose the first guide member46 and the second guide member 47 closer to each other, in comparisonwith when there is not an equivalent of the cutout portion 75 formed atan equivalent of the second guide member 47 or when an equivalent of thebearing 72B is not put inside the equivalent of the cutout portion 75.Thus, according to the illustrative embodiment, it is possible toachieve miniaturization of the ADF 5 as a whole.

Further, according to the aforementioned ADF section 5, a driving forcefrom the motor 35 is transmitted to the shaft 55 via the first powertransmission unit 41, the shaft 54, and the second power transmissionunit 42. Accordingly, although the motor 35 and the shaft 55 aredisposed apart from each other in the axial direction of the shaft 55,the driving force is adequately transmitted from the motor 35 to theshaft 55, and thereby, the shaft 55 and the discharge roller 15A aredriven to rotate. Further, the first power transmission unit 41 and thesecond power transmission unit 42 are disposed to overlap each other ina view in the axial direction of the shafts 54 and 55. Hence, it ispossible to make a region for laying out the first power transmissionunit 41 and the second power transmission unit 42 smaller than when anequivalent of the first power transmission unit 41 and an equivalent ofthe second power transmission unit 42 are disposed not to overlap eachother in a view in the axial direction of the shafts 54 and 55. Thus, itis possible to achieve miniaturization of the ADF section 5.

Further, according to the aforementioned ADF section 5, the second powertransmission unit 42 is configured to transmit a driving force from theshaft 54 to the shaft 55, using the toothed belt 42C. Therefore, it ispossible to make the configuration of the second power transmission unit42 simpler than when a lot of gears form an equivalent of the secondpower transmission unit 42. Further, the shaft 55 is driven to rotate bythe toothed belt 42C, in the same rotational direction as the shaft 54.Therefore, there is no need to crisscross the toothed belt 42C to bewound around the gears 42A and 42B. Thus, it is possible to reduce aload placed on the toothed belt 42C.

Further, according to the aforementioned ADF section 5, the supportingwall 60 is formed in such a shape that the third portion 61C and thefourth portion 62A are recessed toward the sheet conveyance path fromthe first portion 61A and the sixth portion 62C. Then, at the recessedportion (i.e., the third portion 61C and the fourth portion 62A), a partof elements (such as the gears 41D and 41E) included in the first powertransmission unit 41 is attached. Further, at one portion (the firstportion 61A) of two portions adjacent to two ends of the recessedportion in the left-to-right direction, the motor 35 is attached.Furthermore, by the other portion (the sixth portion 62C) of the twoportions adjacent to two ends of the recessed portion in theleft-to-right direction, an end portion of the shaft 54 is supported.

Therefore, unlike an equivalent of the supporting wall 60 formed in aflat plate shape, it is possible to put, to the sheet conveyance path, aregion for disposing a part (such as the gears 41D and 41E) of the firstpower transmission unit 41. Thus, it is possible to reduce a length, inthe axial direction of the shaft 55, of a region occupied by the motor35 and the first power transmission unit 41.

Moreover, to form the supporting wall 60, the first sheet metal member61 including the first to third portions 61A, 61B, and 61C and thesecond sheet metal member 62 including the fourth to sixth portions 62A,62B, and 62C are used. Therefore, it is possible to more easily form, ina press forming method, the supporting wall 60 in a complicated shapeincluding the first to sixth portions 61A, 61B, 61C, 62A, 62B, and 62C(more specifically, in such a shape that the third portion 61C and thefourth portion 62A are recessed toward the sheet conveyance path fromthe first portion 61A and the sixth portion 62C), in comparison withforming the supporting wall 60 from a single sheet metal member. Thus,it is possible to prevent strains caused in the first sheet metal member61 or the second sheet metal member 62.

Further, according to the aforementioned ADF section 5, the dischargeroller 15A is configured to receive the driving force transmitted fromthe motor 35 via the first power transmission unit 41 and the secondpower transmission unit 42. It might cause some delay in transmission ofthe driving force to the discharge roller 15A, in comparison with aconfiguration that the discharge roller 15A receives the driving forcein a position closer to the motor 35 than the position exemplified inthe illustrative embodiment. However, the discharge roller 15A is themost downstream one of rollers disposed along the sheet conveyance pathof the ADF section 5, and is a roller for conveying a sheet for whichimage reading has been completed by the first image sensor 31A and thesecond image sensor 31B. Hence, even though some delay is caused intransmitting the driving force to the discharge roller 15A, it does nothave any negative influence on the quality level of the read images.Thus, the discharge roller 15A is configured in such a preferable mannerthat the shaft 55 of the discharge roller 15A is disposed to overlap themotor 35 in a view in the axial direction of the shaft 55 and spacedapart from the motor 35 in the axial direction of the shaft 55.

Hereinabove, the illustrative embodiment according to aspects of thepresent disclosure has been described. The present disclosure can bepracticed by employing conventional materials, methodology andequipment. Accordingly, the details of such materials, equipment andmethodology are not set forth herein in detail. In the previousdescriptions, numerous specific details are set forth, such as specificmaterials, structures, chemicals, processes, etc., in order to provide athorough understanding of the present disclosure. However, it should berecognized that the present disclosure can be practiced withoutreapportioning to the details specifically set forth. In otherinstances, well known processing structures have not been described indetail, in order not to unnecessarily obscure the present disclosure.

Only an exemplary illustrative embodiment of the present disclosure andbut a few examples of their versatility are shown and described in thepresent disclosure. It is to be understood that the present disclosureis capable of use in various other combinations and environments and iscapable of changes or modifications within the scope of the inventiveconcept as expressed herein.

MODIFICATION

In the aforementioned illustrative embodiment, aspects of the presentdisclosure are applied to the MFP 1 including the reading unit 3 and theADF section 5. For instance, however, aspects of the present disclosuremay be applied to a single-function image scanner.

What is claimed is:
 1. A sheet feeder comprising: a motor; a first shaftconfigured to be driven to rotate by a driving force from the motor, thefirst shaft being spaced apart from the motor in an axial direction ofthe first shaft, the first shaft being disposed to overlap the motorwhen viewed in the axial direction of the first shaft; a first rollersupported by the first shaft and rotatable along with the first shaft,the first roller being configured to convey the sheet downstream in asheet conveyance direction along a sheet conveyance path; and bearingsconfigured to rotatably support two end portions of the first shaft inthe axial direction of the first shaft, wherein the bearings comprise afirst bearing and a second bearing, the second bearing being disposedcloser to the motor than the first bearing, wherein the second bearingcomprises a projection that protrudes in a protruding direction towardthe first shaft from a portion close to the motor, wherein theprojection has an opening formed at a leading end of the projection inthe protruding direction, wherein the second bearing is configured tosupport an end portion of the first shaft inserted into an innercircumferential side of the projection through the opening, and whereinthe projection is disposed to overlap the sheet conveyance path in aview in a direction perpendicular to the protruding direction of theprojection.
 2. The sheet feeder according to claim 1, furthercomprising: a base member; a second shaft configured to be driven torotate by the driving force from the motor; a second roller supported bythe second shaft and rotatable along with the second shaft, the secondroller being configured to convey the sheet downstream in the sheetconveyance direction along the sheet conveyance path; and a first guidemember attached to the base member, the first guide member beingconfigured to define a first conveyance path of the sheet conveyancepath between the first guide member and the base member, the firstconveyance path leading to the first roller from the second roller,wherein the second bearing is formed integrally with the first guidemember.
 3. The sheet feeder according to claim 2, further comprising asecond guide member opposed to the first conveyance path across thefirst guide member, wherein the second guide member is configured todefine a second conveyance path of the sheet conveyance path between thesecond guide member and one or more members opposed to the first guidemember across the second guide member, the second conveyance pathleading to the second roller from upstream relative to the second rollerin the sheet conveyance direction, wherein the second guide member hasone of a hole and a cutout, and wherein the second bearing is at leastpartially put inside the one of the hole and the cutout.
 4. The sheetfeeder according to claim 2, further comprising: a first powertransmission unit configured to transmit the driving force from themotor to an end portion of the second shaft and rotate the second shaft;and a second power transmission unit configured to transmit the drivingforce from another end portion of the second shaft to another endportion of the first shaft and rotate the first shaft.
 5. The sheetfeeder according to claim 4, wherein the first power transmission unitand the second power transmission unit are disposed to overlap eachother in a view in the axial direction of the first shaft and an axialdirection of the second shaft.
 6. The sheet feeder according to claim 4,wherein the second power transmission unit comprises an endless beltwound around the first shaft and the second shaft.
 7. The sheet feederaccording to claim 6, wherein the first shaft is driven to rotate in asame rotational direction as the second shaft, by the endless belt. 8.The sheet feeder according to claim 4, further comprising a supportingwall configured to support the motor, one or more members included inthe first power transmission unit, and the end portion of the secondshaft, wherein the supporting wall comprises: a first sheet metalmember; and a second sheet metal member separate from the first sheetmetal, wherein the first sheet metal member comprises: a first portiondisposed parallel to the sheet conveyance path in a state where athickness direction of the first portion is oriented in a same directionas the axial direction of the first shaft; a second portion that is bentfrom an end of the first portion and extends in such a direction as toapproach the sheet conveyance path; and a third portion that is bentfrom an end of the second portion and disposed parallel to the sheetconveyance path in a position closer to the sheet conveyance path thanthe first portion, wherein the second sheet metal member comprises: afourth portion disposed parallel to the sheet conveyance path in a statewhere a thickness direction of the fourth portion is oriented in thesame direction as the axial direction of the first shaft, the fourthportion being in contact with the third portion in the thicknessdirection of the fourth portion; a fifth portion that is bent from anend of the fourth portion and extends in such a direction as to becomefarther from the sheet conveyance path; and a sixth portion that is bentfrom an end of the fifth portion and disposed parallel to the sheetconveyance path in a position farther from the sheet conveyance paththan the fourth portion, wherein the motor is attached onto a first-sidesurface of the first portion that faces the sheet conveyance path,wherein one or more members included in the first power transmissionunit are attached onto a second-side surface of at least one of thethird portion and the fourth portion, the second-side surface beingopposite to a first-side surface, facing the sheet conveyance path, ofthe at least one of the third portion and the fourth portion, andwherein the end portion of the second shaft is supported by the sixthportion.
 9. The sheet feeder according to claim 1, wherein the firstroller is a discharge roller configured to discharge the sheet toward adownstream end portion of the sheet conveyance path.
 10. The sheetfeeder according to claim 2, wherein the second roller is a turn-aroundroller configured to convey the sheet along an outer circumferentialsurface of the turn-around roller and turn around the sheet conveyancedirection.
 11. An image reader comprising: an image sensor configured toread an image on a sheet in a reading position; and a sheet feederconfigured to feed the sheet to the reading position and discharge thesheet on which the image has been read by the image sensor, the sheetfeeder comprising: a motor; a first shaft configured to be driven torotate by a driving force from the motor, the first shaft being spacedapart from the motor in an axial direction of the first shaft, the firstshaft being disposed to overlap the motor in a view in the axialdirection of the first shaft; and a first roller supported by the firstshaft and rotatable along with the first shaft, the first roller beingconfigured to convey the sheet downstream in a sheet conveyancedirection along a sheet conveyance path; wherein the sheet feederfurther comprises bearings configured to rotatably support two endportions of the first shaft in the axial direction of the first shaft,wherein the bearings comprise a first bearing and a second bearing, thesecond bearing being disposed closer to the motor than the firstbearing, wherein the second bearing comprises a projection thatprotrudes in a protruding direction toward the first shaft from aportion close to the motor, wherein the projection has an opening formedat a leading end of the projection in the protruding direction, whereinthe second bearing is configured to support an end portion of the firstshaft inserted into an inner circumferential side of the projectionthrough the opening, and wherein the projection is disposed to overlapthe sheet conveyance path in a view in a direction perpendicular to theprotruding direction of the projection.
 12. The image reader accordingto claim 11, wherein the first roller is disposed downstream relative tothe reading position in the sheet conveyance direction.
 13. The imagereader according to claim 11, wherein the sheet feeder furthercomprises: a base member; a second shaft configured to be driven torotate by the driving force from the motor; a second roller supported bythe second shaft and rotatable along with the second shaft, the secondroller being configured to convey the sheet downstream in the sheetconveyance direction along the sheet conveyance path; and a first guidemember attached to the base member, the first guide member beingconfigured to define a first conveyance path of the sheet conveyancepath between the first guide member and the base member, the firstconveyance path leading to the first roller from the second roller, andwherein the second bearing is formed integrally with the first guidemember.
 14. The image reader according to claim 13, wherein the sheetfeeder further comprises a second guide member opposed to the firstconveyance path across the first guide member, wherein the second guidemember is configured to define a second conveyance path of the sheetconveyance path between the second guide member and one or more membersopposed to the first guide member across the second guide member, thesecond conveyance path leading to the second roller from upstreamrelative to the second roller in the sheet conveyance direction, whereinthe second guide member has one of a hole and a cutout, and wherein thesecond bearing is at least partially put inside the one of the hole andthe cutout.
 15. The image reader according to claim 13, wherein thesheet feeder further comprises: a first power transmission unitconfigured to transmit the driving force from the motor to an endportion of the second shaft and rotate the second shaft; and a secondpower transmission unit configured to transmit the driving force fromanother end portion of the second shaft to another end portion of thefirst shaft and rotate the first shaft.
 16. The image reader accordingto claim 15, wherein the first power transmission unit and the secondpower transmission unit are disposed to overlap each other in a view inthe axial direction of the first shaft and an axial direction of thesecond shaft.
 17. The image reader according to claim 15, wherein thesecond power transmission unit comprises an endless belt wound aroundthe first shaft and the second shaft.
 18. The image reader according toclaim 15, wherein the sheet feeder further comprises a supporting wallconfigured to support the motor, one or more members included in thefirst power transmission unit, and the end portion of the second shaft,wherein the supporting wall comprises: a first sheet metal member; and asecond sheet metal member separate from the first sheet metal, whereinthe first sheet metal member comprises: a first portion disposedparallel to the sheet conveyance path in a state where a thicknessdirection of the first portion is oriented in a same direction as theaxial direction of the first shaft; a second portion that is bent froman end of the first portion and extends in such a direction as toapproach the sheet conveyance path; and a third portion that is bentfrom an end of the second portion and disposed parallel to the sheetconveyance path in a position closer to the sheet conveyance path thanthe first portion, wherein the second sheet metal member comprises: afourth portion disposed parallel to the sheet conveyance path in a statewhere a thickness direction of the fourth portion is oriented in thesame direction as the axial direction of the first shaft, the fourthportion being in contact with the third portion in the thicknessdirection of the fourth portion; a fifth portion that is bent from anend of the fourth portion and extends in such a direction as to becomefarther from the sheet conveyance path; and a sixth portion that is bentfrom an end of the fifth portion and disposed parallel to the sheetconveyance path in a position farther from the sheet conveyance paththan the fourth portion, wherein the motor is attached onto a first-sidesurface of the first portion that faces the sheet conveyance path,wherein one or more members included in the first power transmissionunit are attached onto a second-side surface of at least one of thethird portion and the fourth portion, the second-side surface beingopposite to a first-side surface, facing the sheet conveyance path, ofthe at least one of the third portion and the fourth portion, andwherein the end portion of the second shaft is supported by the sixthportion.